Food may be prepared by cooking on various heating appliances. Examples include barbecue and oven. Typically the food is laid out horizontally or in two dimensions on a grill, rack or pan. On a barbecue an elongated item such as a back rib, chicken wing or leg for example will be strongly exposed on its downward side to the heat source requiring frequent turning for even cooking. In an oven pan a food item will soak in its juices which may cause sogginess or be unhealthful for meats with fats.